1. Field of the Invention
The present invention relates to an image forming device such as a laser printer, and particularly to a process cartridge provided in the image forming device.
2. Description of Related Art
Laser printers and other image forming devices equipped with a detachably mounted process cartridge are well known in the art. The process cartridge includes a developing roller for carrying a toner; a photosensitive drum disposed in confrontation with the developing roller, on the surface of which electrostatic latent images are formed; and a transfer roller disposed in opposition to the photosensitive drum, to which a transfer bias is applied.
When the toner carried on the developing roller comes into opposition with and contacts the photosensitive drum, the latent images on the drum are developed into a toner image that is carried on the surface of the photosensitive drum. Subsequently, by applying a transfer bias to the transfer roller, the toner image is transferred onto paper as the paper passes between the photosensitive drum and the transfer roller.
In this type of laser printer, toner remaining on the surface of the photosensitive drum after the toner image has been transferred to the paper by the transfer roller is recovered by the developing roller in what is known as a cleanerless system. In the cleanerless system, a paper dust collecting brush is disposed downstream of the transfer roller with respect to the rotational direction of the photosensitive drum for recovering paper dust deposited from paper onto the surface of the photosensitive drum.
One such paper dust collecting brush has been proposed in Japanese patent-application publication (kokai) No. HEI-9-244503. The brush includes a planar part having an implantation surface with a flat rectangular shape; a brush material of a predetermined height that is thickly implanted in the implantation surface; protruding parts disposed on one of the longer side edges on the implantation surface, rising nearly perpendicular to the implantation surface up to a predetermined position lower than the height of the brush material and then folding back and downward from this predetermined position; and a mounting plate part extending from the lower end of the protruding parts in a direction intersecting the same.